The cytoskeleton is: the skeleton within the cytoplasm; the “infrastructural highway;” or “the network of protein filaments and microtubules (made of tubulin, a globular protein) in the cells that controls cell shape, maintains intracellular organization, and is involved in cell movement.” It “influences the shape of the cell in much the same way tent poles determine the shape of a tent. Without the cytoskeleton a cell tends to become spherical.” http://www.cellsalive.com/cells/cell_model.htm (See this website for an interactive view of the cytoskeleton. Animal or plant cell--> centrioles, centrosome, cytoskeleton.)
This is a picture of a eukaryotic cytoskeleton.
Nine triplet sets of microtubules form a centriole. The centrosome is then formed with two centrioles. These three structures form the cytoskeleton.
The cytoskeleton is found in both prokaryotes and eukaryotes.
The cytoskeleton’s functions include:
1) maintains cell shape
2) protects cell
3) enables cellular motion
4) helps intracellular transport
5) helps cellular division http://www.fofweb.com/Science/default.asp?ItemID=WE40 (Type "cytoskeleton" into Basic Search box. Click on the second link "Cell Interior: Cytoskeleton and Organelles." The beginning of this video talks about the cytoskeleton and some of its functions.)
Eukaryotic cells contain three kinds of cytoskeletal filaments:
1) microfilaments
2) intermediate filaments
3) microtubules
Microtubules are:
1) made of 13 protofilaments (polymers of alpha and beta globular proteins)
2) hollow cylinders 25 nm in diameter
The microtubule’s functions include:
1) intracellular transport of the “inner core” (axoneme) of cilia and flagella. The axoneme consists of many microtubules.
2) mitotic spindle
3) synthesis of the cell wall in plants
The following drugs affect mitotic spindle:
1) Colchicine binds to tubulin (protein that makes up microtubules). This may cause cancer cells to be poisoned because there is an increased rate of mitosis in cancer cells.
2) Vincristine “inhibits microtubule formation in mitotic spindle, resulting in an arrest of dividing cells at the metaphase stage.”
3) Vinblastine “binds to tubulin and inhibits microtubule formation, resulting in disruption of mitotic spindle assembly and arrest of tumor cells in the M phase of the cell cycle.”
Recent Research:
Dr. Tanniemola Liverpool was awarded a grant for a collaborative project entitled ‘Microscopic models of cross-linked active gels.’ The project brings together the USA, UK, and Africa. They will study a “new class of soft materials maintained out of equilibrium by internal energy sources.” The cytoskeleton controls many processes for the cell, but for many of these processes, how they occur is still unknown. The aim of the project is to “design a new generation of smart materials at the nanoscale” by studying “the processes controlling the complex mechanical properties of the cytoskeleton.”
Date: July 24, 2008
"Maths Grant for International Research on Biomaterials." Bristol University
News from the University Maths Grant. 24 July 2008. University of Bristol.
16 Oct. 2008 <http://www.bristol.ac.uk/news/2008/212017945461.html>.
What is the Cytoskeleton?
Cytoskeleton is the cellular framework found in the cytoplasm of both, eukaryotic cells and prokaryotic cells. Also known as CSK, cytoskeleton has “a dynamic structure that maintains cell shape, protects the cell, enables cellular motion, and plays important roles in both intracellular transport and cellular division.”
"The image [above] shows the standard deviation of intensity at each pixel over the course of a fluorescent movie of microtubules in a drosophila S2 cell."
Microtubules:
Structure:
Microtubules are heterodimers that is they are “composed of one alpha tubulin and one beta tubulin bound together.” The Alpha and beta rotate to create a protofilament, and thirteen protofilaments tangentially connect to form a microtubule.
Functions:
The functions of microtubules include:
*Varied usus during mitosis (Mitotic Spindle)
*Vesicle transport and chromosome segregation
*Microtubules may also join with other proteins to form more complex structures called cilia, flagella or centrioles
This is the Mitotic Spindle at four different stages
Adverse affects by drugs:
*Colchicines induce the mitotic arrest by inhibiting microtubule polymerization, effectively destroying the mitotic spindle.
*"Vinceristine[, a vinca alkaloid, is a mitotic inhibitor, and] is also used in cancer chemotherapy."
*Vinblastine "blocks mitosis in cells with little or no depolymerization of spindle microtubules."
Contemporary Research:
"Eva Nogales and Hong-Wei Wang of the Life Sciences Division of the Department of Energy's Lawrence Berkeley National Laboratory have revealed at molecular level the forms taken by transitional structures of tubulin (the protein from which microtubules are formed) during the assembly and disassembly of microtubules. Details of these peculiar structures show how the binding to tubulin of the nucleotide guanosine triphosphate, GTP, controls activity at the growing end of the microtubule".
Works Cited (In progress)
Brown, Andre E.X. Andre Brown. 23 June 2008. 22 Oct. 2008 <http://student.physics.upenn.edu/~aebrown/research.html>. Childs, Gwen V. Graduate Biology . Course home page. 5 Dec. 2003. Cell Biology Graduate Program, University of Texas. 19 Oct. 2008 <http://cellbio.utmb.edu/microanatomy/>. “Cytoskeleton.” Cytoskeleton. Dec. 2007. Wikipedia. 19 Oct. 2008 <http://en.wikipedia.org/wiki/Cytoskeleton>. “Cytoskeleton.” Cytoskeleton. 22 Oct. 2008 <http://www.biologyreference.com/Co-Dn/Cytoskeleton.html>. “MIC - Gallery confocal microscopes.” Gallery confocal microscopes. MIC. 22 Oct. 2008 <http://www.uib.no/med/mic/gallery/pages/mitotic-spindle.html>.
=
=Cytoskeleton: Microtubules
Mary Dambro
Cytoskeleton: Microtubules
The cytoskeleton is: the skeleton within the cytoplasm; the “infrastructural highway;” or “the network of protein filaments and microtubules (made of tubulin, a globular protein) in the cells that controls cell shape, maintains intracellular organization, and is involved in cell movement.” It “influences the shape of the cell in much the same way tent poles determine the shape of a tent. Without the cytoskeleton a cell tends to become spherical.”
http://www.cellsalive.com/cells/cell_model.htm (See this website for an interactive view of the cytoskeleton. Animal or plant cell--> centrioles, centrosome, cytoskeleton.)
This is a picture of a eukaryotic cytoskeleton.
Nine triplet sets of microtubules form a centriole. The centrosome is then formed with two centrioles. These three structures form the cytoskeleton.
The cytoskeleton is found in both prokaryotes and eukaryotes.
The cytoskeleton’s functions include:
1) maintains cell shape
2) protects cell
3) enables cellular motion
4) helps intracellular transport
5) helps cellular division
http://www.fofweb.com/Science/default.asp?ItemID=WE40 (Type "cytoskeleton" into Basic Search box. Click on the second link "Cell Interior: Cytoskeleton and Organelles." The beginning of this video talks about the cytoskeleton and some of its functions.)
Eukaryotic cells contain three kinds of cytoskeletal filaments:
1) microfilaments
2) intermediate filaments
3) microtubules
Microtubules are:
1) made of 13 protofilaments (polymers of alpha and beta globular proteins)
2) hollow cylinders 25 nm in diameter
The microtubule’s functions include:
1) intracellular transport of the “inner core” (axoneme) of cilia and flagella. The axoneme consists of many microtubules.
2) mitotic spindle
3) synthesis of the cell wall in plants
The following drugs affect mitotic spindle:
1) Colchicine binds to tubulin (protein that makes up microtubules). This may cause cancer cells to be poisoned because there is an increased rate of mitosis in cancer cells.
2) Vincristine “inhibits microtubule formation in mitotic spindle, resulting in an arrest of dividing cells at the metaphase stage.”
3) Vinblastine “binds to tubulin and inhibits microtubule formation, resulting in disruption of mitotic spindle assembly and arrest of tumor cells in the M phase of the cell cycle.”
Recent Research:
Dr. Tanniemola Liverpool was awarded a grant for a collaborative project entitled ‘Microscopic models of cross-linked active gels.’ The project brings together the USA, UK, and Africa. They will study a “new class of soft materials maintained out of equilibrium by internal energy sources.” The cytoskeleton controls many processes for the cell, but for many of these processes, how they occur is still unknown. The aim of the project is to “design a new generation of smart materials at the nanoscale” by studying “the processes controlling the complex mechanical properties of the cytoskeleton.”
Date: July 24, 2008
Works Cited
American Lung Association. "Glossary." Glossary - American Lunch Association
Site. 2008. American Lung Association. 13 Oct. 2008
<http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=40415#c>.
"Cell Interior: Cytoskeleton and Organelles." Films Media Group. Cells: As
Introduction. Ed. Facts on File, Inc. Science Online. 17 Oct. 2008
<http://www.fofweb.com/Subscription/Default.asp?BID=7>.
"Colchicine." Weblog post. Colchicine. 20 Apr. 2007. 13 Oct. 2008
<http://en.wikipedia.org/wiki/Colchicine>.
"Cytoskeleton." Weblog post. Cytoskeleton. Dec. 2007. 13 Oct. 2008
<http://en.wikipedia.org/wiki/Cytoskeleton>.
Eukaryotic Cell interactive Animation. Cells Alive. 12 Oct. 2008
<http://www.cellsalive.com/cells/cell_model.htm>.
"Maths Grant for International Research on Biomaterials." Bristol University
News from the University Maths Grant. 24 July 2008. University of Bristol.
16 Oct. 2008 <http://www.bristol.ac.uk/news/2008/212017945461.html>.
"Mitotic Spindle." Weblog post. Mitotic Spindle. 2006. 13 Oct. 2008
<http://en.wikipedia.org/wiki/Mitotic_spindle>.
Scientific American. "Cell Structure." Cell Structure - Biology Online.
Scientific American. 13 Oct. 2008 <http://www.biology-online.org/9/
2_cell_structure.htm>.
"Vinblastine." Definition of Vinblastine - National Cancer Institute Drug
Dictionary. National Cancer Institute. 17 Oct. 2008
<http://www.cancer.gov/Templates/drugdictionary.aspx?CdrID=42951>.
"Vincristine." Vincristine Official FDA Information, Side Effects and Uses. Mar.
2007. 11 Oct. 2008 <http://www.drugs.com/pro/vincristine.html>.
Fluorescent Cells. Photograph. Wikipedia. 15 Oct. 2008
<http://en.wikipedia.org/wiki/Image:FluorescentCells.jpg>.
http://www.2facts.com/wae/search/xce079700a.asp?DBType=ICOF#xce079700a_5
Cytoskeleton: Microtubules
Kishun Kurani
Period (G)
What is the Cytoskeleton?
Cytoskeleton is the cellular framework found in the cytoplasm of both, eukaryotic cells and prokaryotic cells. Also known as CSK, cytoskeleton has “a dynamic structure that maintains cell shape, protects the cell, enables cellular motion, and plays important roles in both intracellular transport and cellular division.”
"The image [above] shows the standard deviation of intensity at each pixel over the course of a fluorescent movie of microtubules in a drosophila S2 cell."
Microtubules:
Structure:
Microtubules are heterodimers that is they are “composed of one alpha tubulin and one beta tubulin bound together.” The Alpha and beta rotate to create a protofilament, and thirteen protofilaments tangentially connect to form a microtubule.
Functions:
The functions of microtubules include:
*Varied usus during mitosis (Mitotic Spindle)
*Vesicle transport and chromosome segregation
*Microtubules may also join with other proteins to form more complex structures called cilia, flagella or centrioles
Adverse affects by drugs:
*Colchicines induce the mitotic arrest by inhibiting microtubule polymerization, effectively destroying the mitotic spindle.
*"Vinceristine[, a vinca alkaloid, is a mitotic inhibitor, and] is also used in cancer chemotherapy."
*Vinblastine "blocks mitosis in cells with little or no depolymerization of spindle microtubules."
Contemporary Research:
"Eva Nogales and Hong-Wei Wang of the Life Sciences Division of the Department of Energy's Lawrence Berkeley National Laboratory have revealed at molecular level the forms taken by transitional structures of tubulin (the protein from which microtubules are formed) during the assembly and disassembly of microtubules. Details of these peculiar structures show how the binding to tubulin of the nucleotide guanosine triphosphate, GTP, controls activity at the growing end of the microtubule".
Works Cited (In progress)
Brown, Andre E.X. Andre Brown. 23 June 2008. 22 Oct. 2008 <http://student.physics.upenn.edu/~aebrown/research.html>.
Childs, Gwen V. Graduate Biology . Course home page. 5 Dec. 2003. Cell Biology Graduate Program, University of Texas. 19 Oct. 2008 <http://cellbio.utmb.edu/microanatomy/>.
“Cytoskeleton.” Cytoskeleton. Dec. 2007. Wikipedia. 19 Oct. 2008 <http://en.wikipedia.org/wiki/Cytoskeleton>.
“Cytoskeleton.” Cytoskeleton. 22 Oct. 2008 <http://www.biologyreference.com/Co-Dn/Cytoskeleton.html>.
“MIC - Gallery confocal microscopes.” Gallery confocal microscopes. MIC. 22 Oct. 2008 <http://www.uib.no/med/mic/gallery/pages/mitotic-spindle.html>.